Add ability for some command-line options to have a sequence of values.
Add ability for some command-line options to have a sequence of values.

strubell/factorie,digitalreasoning/factorie-scala-210,pogren-oracle/factorie,melisabok/factorie,patverga/factorie,joprice/factorie,malcolmgreaves/factorie,Craigacp/factorie,zxsted/factorie,hlin117/factorie,factorie/factorie,asubbaswamy/factorie